Targeted Bisulfite Sequencing Using the SeqCap Epi Enrichment System

Cytosine methylation has been shown to have a role in a host of biological processes. In mammalian biology these include stem cell differentiation, embryonic development, genomic imprinting, inflammation, and silencing of transposable elements. Given the central importance of these processes, it is not surprising to find aberrant cytosine methylation patterns associated with many disorders in humans, including cancer, cardiovascular disease, and neurological disease. While whole genome shotgun bisulfite sequencing (WGBS) has recently become feasible, generating high sequence coverage data for the entire genome is expensive, both in terms of money and analysis time, when generally only a small subset of the genome is of interest to most researchers. This report details a procedure for the targeted enrichment of bisulfite treated DNA via SeqCap Epi, allowing high resolution focus of next generation sequencing onto a subset of the genome for high resolution cytosine methylation analysis. Regions ranging in size from only a few kb up to over 200 Mb may be targeted, including the use of the SeqCap Epi CpGiant design which is designed to target 5.5 million CpGs in the human genome. Finally, multiple samples may be multiplexed and sequenced together to provide an inexpensive method of generating methylation data for a large number of samples in a high throughput fashion.